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Old 10-08-2018, 03:52 PM   #1
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My best guess is: worn chain tensioners, worn chain rails, or worn vairocam rails if your car has them. Could be all three. It could also be stretching chains.

Have you checked camshaft deviations and, if so, do you have past numbers to check them against. I believe changing deviations over time suggest wearing rails or stretching chains

You could also check the sump for black or brown plastic pieces to see if the rails are wearing.

Tensioners are cheapest to replace; variocam rails next and internal chain rails are the most expensive requiring a complete tear down.
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Old 10-08-2018, 04:21 PM   #2
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Originally Posted by thom4782 View Post
My best guess is: worn chain tensioners, worn chain rails, or worn vairocam rails if your car has them. Could be all three. It could also be stretching chains.

Have you checked camshaft deviations and, if so, do you have past numbers to check them against. I believe changing deviations over time suggest wearing rails or stretching chains

You could also check the sump for black or brown plastic pieces to see if the rails are wearing.

Tensioners are cheapest to replace; variocam rails next and internal chain rails are the most expensive requiring a complete tear down.

Thanks for sharing your thoughts. I have zero chain rattle at cold start-up, that really puzzles me to doubt tensioners/ rails. 3 oil changes in the past 15K miles of my ownership came out with zero plastic or metallic debris in oil filters, but it is due now so I’ll check it out again. My car has 85K miles and it runs like a champ and revs smooth beside this strange, very isolated noise.

I never checked cam deviation, I’ll look into it. Anybody here around Detroit with the proper scanner? I got Autel with no such ability...
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Old 10-08-2018, 05:07 PM   #3
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Thanks for sharing your thoughts. I have zero chain rattle at cold start-up, that really puzzles me to doubt tensioners/ rails. 3 oil changes in the past 15K miles of my ownership came out with zero plastic or metallic debris in oil filters, but it is due now so I’ll check it out again. My car has 85K miles and it runs like a champ and revs smooth beside this strange, very isolated noise.

I never checked cam deviation, I’ll look into it. Anybody here around Detroit with the proper scanner? I got Autel with no such ability...
My filter was clean in my first ever oil change. I then dropped the sump to install a guardian. There was little bit of those chain ramp plastic in the sump. I was always thinking they might never reach the oil filter because they are to heavy to suspend in the oil and reach the filter.
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Old 10-08-2018, 06:06 PM   #4
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My filter was clean in my first ever oil change. I then dropped the sump to install a guardian. There was little bit of those chain ramp plastic in the sump. I was always thinking they might never reach the oil filter because they are to heavy to suspend in the oil and reach the filter.
Do you also suspect worn tensioners to be the issue?

I have seen many posts with pictures of plastics debris caught in the oil filter paper pleats, but I might drop the pan too see. I got the drain plug with magnetic tip and so far metallic debris are nothing alarming.
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